Device for Mounting Battery Cells of a Battery Pack

ABSTRACT

A device which holds rechargeable batteries cells in a battery pack, in particular for a handheld electric tool, with a first holding part and a second holding part which together with the interposed battery cells can be joined and affixed to one another. The invention includes protrusions of the first holding part extending in the assembly direction which are formed with a yieldable outer periphery, so that they can be inserted into and locked in openings formed in the second holding part.

BACKGROUND OF THE INVENTION

The invention is directed to a device for mounting battery cells of abattery pack, in particular for a handheld electric tool, with a firstholding part and a second holding part which can be joined and lockedonto one another by interposing the rechargeable battery cells.

Such devices are generally known. The first holding part is connected toand locked onto the second holding part by a clip connection. However,with the clip connection, the first holding part and the second holdingpart can only be secured with respect to one another with a certainspacing, making such devices suitable only for battery cells of acertain geometry, in particular battery cells having a certain height.

In another device, the first holding part is connected with the secondholding part by a screw connection which, however, is time-consuming.

BRIEF SUMMARY OF THE INVENTION

It is an object of the invention to provide a device which can be moreeasily assembled.

This object is attained by the invention with a device whereinprotrusions of the first holding part extending in the assemblydirection are formed with a yieldable outer periphery, so that they canbe inserted into openings of the second holding part and locked therein.

Although the openings have an inside contour which is substantiallycomplementary to the outer contour of the protrusions, the openings areslightly tapered towards the outer contour, so that the protrusions ofthe first holding part can be lockingly secured in the openings.

Through latching with the protrusions, battery cells of different heightcan be gripped with the device of the invention. The assembly process isalso simplified substantially. A yieldable outside diameter is definedas a diameter which can change, in particular be tapered, perpendicularto the assembly direction,.

In an advantageous embodiment of the device of the invention, theprotrusions are formed as pins. The protrusions extend as columns in theassembly direction from the first holding part towards the secondholding part. Advantageously, the device is compact and openperpendicular to the assembly direction.

In one exemplary embodiment of the invention, the outer periphery of theprotrusions has a slightly tapered, in particular conical contour. Theprotrusions can then be easily inserted into the openings withoutrequiring exactly alignment.

The tapered outer periphery of the protrusions is preferably inclined byan angle of 0.5° to 3.0° with respect to the assembly direction.

In an advantageous exemplary embodiment of the invention, theprotrusions have at least one slot. The at least one slot can extend inthe assembly direction and can be contiguous throughout the protrusion,i.e., the slot can divide the protrusion into segments. Alternatively,several slots in form of a cross slot arrangement may be provided.Preferably, the protrusion has a slot that extends in the assemblydirection and ends at the free end of the protrusion, as viewed in theassembly direction. The segments of the protrusion formed in this mannercan the move towards one another or be pressed against each other. Thisarrangement realizes a yieldable outer periphery.

In a preferred exemplary embodiment of the device, the first holdingpart and the protrusions are formed as a single piece or from separateindividual components. The protrusions and the first holding part cantherefore be produced in a single common injection molding process orcan be assembled in a later processing step. Advantageously, the firstholding part and the second holding part can be used for differentbattery cells of significantly different height, wherein the protrusionsneed only match the height of the actually employed batteries.

In another modification of the aforedescribed device, the first and/orthe second holding part include spacer elements which each separate twoadjacent battery cells. The spacer elements can be formed as a singlepiece with the first or the second holding part or can be attached asseparate components to the first or second holding part. Advantageously,by separating the adjacent battery cells, the battery cells may beprevented from contacting each other so that even battery cells whichare not electrically insulated can be used.

According to yet another exemplary embodiment of the device, theopenings of the second holding part have a tapered interior contour and,more particularly, are conically shaped.

According to an advantageous embodiment of the device of the invention,the first holding part and/or the second holding part have frame means,which secure the battery cells and prevent them from movingperpendicular to the assembly direction. For example, the frame meansmay be formed as one piece with the holding parts; alternatively, theframe means may be separate individual components, which are made of oneor several separate individual components and are inserted into theholding parts. The frame means are formed with a geometry that iscomplementary to the geometry of the battery cell, so that the batterycells are positively locked by the frame means. This prevents thebattery cells from wobbling in the holding parts.

In a particularly preferred exemplary embodiment of the device, theframe means are formed as openings or recesses in the first and/or inthe second holding part. The frame means is hence an integral componentof the first and/or second holding part, resulting in a very compactdevice with a small parts count.

In a modified embodiment of the aforedescribed invention, the framemeans have in the assembly direction an opening extending through thefirst and/or the second holding part, making a battery cell accessiblefrom the outside. In this way, the battery cells can be contacted orwelded to each other, for example by using contact sheets.

Moreover, in another exemplary embodiment of the device, the firstand/or the second holding part, including the protrusions, is preferablyformed as a plastic injection molded part.

Advantageously, the first and/or the second holding part have a limitstop in the assembly direction. By providing a limit stop, the devicecan be adapted to battery cells of a defined size, wherein the assembleddevice has a predefined height.

In yet another exemplary embodiment of the device, the limit stop isformed on the protrusions as a shoulder perpendicular to the assemblydirection.

Additional features, details and advantages of the invention are recitedin the dependent claims and the drawings and in the followingdescription of a preferred embodiment of the invention.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING

The drawing shows in:

FIG. 1 a perspective view of a first holding part of a device accordingto the invention;

FIG. 2 a perspective view of a second holding part of the deviceaccording to the invention; and

FIG. 3 a perspective view of the assembled device according to theinvention.

DETAILED DESCRIPTION OF THE INVENTION

The figures illustrate a device 2 for mounting rechargeable batterycells 4 in a battery pack, wherein a first holding part 6 can beconnected with a second holding part 8. The first holding part 6 hasprotrusions which extend in an assembly direction 10 and can be insertedinto openings 14 of the second holding part 8, where they can be lockedin position.

FIG. 1 shows the first holding part 6 of the device 2 with theprotrusions 12 being formed with the first holding part 6 as a singlepart. The protrusions 12 have a conical outer contour and a slot 16 withan open edge towards the free end. With the open slot 16, the respectiveprotrusion 12 can be pressed together by moving the sections created bythe slot 16 towards one another. This produces the yieldable outerperiphery. In addition, the protrusions 12 have each a limit stop 20implemented as a shoulder 18.

In addition to the protrusions 12, spacer elements 22 separating theinstalled battery cells 4 are arranged on the first holding part 6. Thespacer elements 22, like the protrusions 12, have shoulders 18 which canoperate as a limit stop.

Spacer elements 22 and protrusions 12 are arranged between frame means24 of the first mounting part; these space the battery cells 4, whichare not illustrated in FIG. 1, apart from one another. The frame means24 are hereby formed by cavities 26 extending in the assembly direction10. The frame means 24 are used to secure the battery cells 4perpendicular to the assembly direction. The first holding part 6 alsohas a limit stop 29 formed by a wall 28.

FIG. 2 shows the second holding part 8 with openings 14 configured tocomplement the protrusions 12. Moreover, the second holding part 8 haslikewise spacer elements 22 which are configured to contact in an endposition the shoulders 18 of the spacer elements 22 of the firstmounting part 6. The second mounting part 8 also has frame means 24formed by indentations 26.

FIG. 2 shows more clearly that the cavities 26 in the first holding part6 and in the second holding part 8 are formed as a passageway 32 with anaxial material edge 30 that prevents the battery cells 4 from slidingout. The battery cells 4 can be accessed and contacted from the outsidevia this passageway. The passageways 32 are formed in both the firstholding part 6 and in the second holding part 8.

FIG. 3 shows the assembled device 2. The battery cells 4 are herebyarranged between the first holding part 6 and the second holding part 8.The first holding part 6 and the second holding part 8 are inserted intoone another and contact each other at limit stop 20, thereby preventingfurther relative movement between the two holding parts in the assemblydirection 10. FIG. 3 also illustrates that, after the first holding part6 and the second holding part 8 have been assembled, the battery cellsare contacted by a metal sheet 34, so that they cooperate in a batterypack.

Thus, while there have been shown and described and pointed outfundamental novel features of the invention as applied to a preferredembodiment thereof, it will be understood that various omissions andsubstitutions and changes in the form and details of the devicesillustrated, and in their operation, may be made by those skilled in theart without departing from the spirit of the invention. For example, itis expressly intended that all combinations of those elements and/ormethod steps which perform substantially the same function insubstantially the same way to achieve the same results are within thescope of the invention. Substitutions of elements from one describedembodiment to another are also fully intended and contemplated. It isalso to be understood that the drawings are not necessarily drawn toscale but that they are merely conceptual in nature. It is theintention, therefore, to be limited only as indicated by the scope ofthe claims appended hereto.

1. A device for securing rechargeable battery cells in a battery pack,comprising: a first holding part having protrusions extending in anassembly direction and being formed with a yieldable outer periphery,and a second holding part having openings adapted to mate with theprotrusions, wherein the battery cells are interposed between the firstholding part and the second holding part, and the first holding part andthe second holding part are joined and affixed to one another byinserting the protrusions into the openings to form the battery pack. 2.The device of claim 1, wherein the protrusions are formed as pins. 3.The device of claim 1, wherein an outer periphery of the protrusions istapered.
 4. The device of claim 3, wherein the tapered outer peripheryof the protrusions has a conical contour
 5. The device of claim 3,wherein the taper of the protrusions encloses an angle of 0.5° to 3.0°with the assembly direction.
 6. The device of claim 1, wherein theprotrusions include a slot.
 7. The device of claim 1, wherein the firstholding part and the protrusions are formed as a single piece.
 8. Thedevice of claim 1, wherein the first holding part and the protrusionsare formed from separate individual components.
 9. The device of claim1, wherein at least one of the first and second holding parts comprisesspacer elements, with the spacer elements separating adjacent batterycells.
 10. The device of claim 1, wherein the openings of the secondholding part have a tapered inside contour.
 11. The device of claim 10,wherein the inside contour of the openings has a conical shape.
 12. Thedevice of claim 1, wherein at least one of the first holding part andthe second holding part comprises a frame which secures the batterycells against movement perpendicular to the assembly direction.
 13. Thedevice of claim 12, wherein the frame comprises openings or recesses inat least one of the first holding part and the second holding part. 14.The device of claim 12, wherein the frame comprises, in the assemblydirection, a passageway extending through at least one of the firstholding part and the second holding part, with the passageway providingexternal access to the battery cells.
 15. The device of claim 1, whereinat least one of the first holding part and the second holding part isformed as an injection molded plastic part.
 16. The device of claim 1,wherein at least one of the first holding part and the second holdingpart comprises a limit stop in the assembly direction.
 17. The device ofclaim 16, wherein the limit stop is formed as a shoulder disposed on theprotrusions perpendicular to the assembly direction.
 18. The device ofclaim 16, wherein the device is configured for installation in ahandheld electric tool.